package com.company.mogu;

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        int y = sc.nextInt();
        x+=2;
        y+=2;
        int[][] map = new int[x][y];

        for (int i = 0; i < y; i++) {
            map[0][i] = 1;
        }
        for (int i = 0; i < x; i++) {
            map[i][0] = 1;
        }

        for (int i = 1; i < x; i++) {
            for (int j = 1; j < y; j++) {
                map[i][j] = map[i - 1][j] + map[i][j - 1];
            }
        }

        System.out.println(map[x - 2][y - 2]);
    }

}
